This application claims the benefit of Korean Patent Application No. 2002-44211 filed on Jul. 26, 2002 and Korean Patent Application No. 2002-44212 filed on Jul. 26, 2002 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to wall-mounted microwave ovens, and more particularly to a smoke guiding apparatus of a wall-mounted microwave oven, which guides smoke generated therebelow to an exhaust path of the microwave oven.
2. Description of the Related Art
Generally, a wall-mounted microwave oven is installed on a wall surface, above an oven range, and functions as a hood to suck steam and smoke generated from food cooked therebelow, and discharge them to the outside of a cooking area.
FIG. 1 shows the construction of a smoke guiding apparatus of a conventional wall-mounted microwave oven.
Referring to FIG. 1, a body 1 of the wall-mounted microwave oven includes a cooking chamber (not shown) to cook food therein and a machine room (not shown) which stores various machine parts. The cooking chamber and the machine room are partitioned from one another. The body 1 of the microwave oven further includes an exhaust fan 3 which is installed in an upper portion of a back of the body 1 so as to exhaust gas or smoke generated from an oven range 2, which is positioned below the body 1. An exhaust inlet (not shown) is formed in a lower portion of the body 1 so as to suck the gas or smoke where the exhaust fan 3 is operated. An exhaust path 4 is formed within the body 1 to guide the gas or smoke sucked into the exhaust inlet to the exhaust fan 3.
Moreover, a smoke guiding apparatus 5 is installed beneath the body 1 so as to guide the smoke therebelow to the exhaust inlet. The smoke guiding apparatus 5 comprises a limit switch 8, a feed motor 9 and a microcomputer 10. The limit switch 8 is provided to be turned on or off according to a moving position of a guide plate 7. The guide plate 7 is inserted into a guide groove of a guide member 6 to move straight forward and backward. The feed motor 9 moves the guide plate 7 by rotating forwardly or reversely in response to a control signal output from the microcomputer 10.
The microcomputer 10 controls forward/reverse rotation of the feed motor 9, or stops the rotation of the feed motor 9 in response to an output signal of the limit switch 8. In a gear shaft of the feed motor 9, a pinion gear 12 engages with a rack gear 11 formed beneath the guide plate 7, thus enabling the guide plate 7 to move forward and backward according to the rotation of the feed motor 9. For example, two grooves are formed in the guide plate 7 in a progress direction of the guide plate 7. The limit switch 8 is constructed to output different output signals according to positions of a moving surface and the two grooves of the guide plate 7.
In the conventional smoke guiding apparatus 5, the microcomputer 10 reads an output signal of the limit switch 8, and controls the feed motor 9 based upon the output signal, thus allowing the guide plate 7 to move to a guide position or an initial position (original position) of the guide plate 7.
However, the conventional smoke guiding apparatus 5 is problematic in that it increases the entire manufacturing cost thereof by employing the microcomputer 10. Further, it cannot be applied to mechanical microwave ovens which do not employ a microcomputer.
Accordingly, an aspect of the present invention is to provide a driving circuit, which is not additionally provided with a microcomputer to control a smoke guiding apparatus of a microwave oven. The driving circuit drives the smoke guiding apparatus through limit switches which are turned on or off according to a moving position of a guide plate of the smoke guiding apparatus, a relay coil which is supplied with power where an exhaust motor is operated, and a plurality of relay switches which are turned on or off by the supply of the power to the relay coil.
Another aspect of the present invention is to provide a driving circuit, which drives a smoke guiding apparatus of a microwave oven where a DC feed motor is applied to the smoke guiding apparatus.
Yet another aspect of the present invention is to provide a driving circuit, which drives a smoke guiding apparatus of a microwave oven where an AC feed motor is applied to the smoke guiding apparatus.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
To achieve the above and/or other aspects of the present invention, there is provided an embodiment of the present invention which includes a controller for a smoke guiding apparatus of a wall-mounted microwave oven having an exhaust motor which discharges smoke therebelow to the outside of the wall-mounted microwave oven, a guide plate which guides the smoke, and a feed motor which moves the guide plate between an initial position and a guide position of the guide plate, the controller comprising a switching unit which supplies power to the feed motor so as to move the guide plate between the guide position and the initial position in conjunction with an operation of the exhaust motor, a first limit switch which shuts off the power supplied to the feed motor in response to the guide plate reaching the guide position, and a second limit switch which shuts off the power supplied to the feed motor in response to the guide plate reaching the initial position.
To achieve the above and/or other aspects of the present invention, there is provided another embodiment of a controller for a smoke guiding apparatus of a wall-mounted microwave oven having an exhaust motor which discharges smoke therebelow to the outside of the wall-mounted microwave oven, a guide plate which guides the smoke, and a feed motor which receives DC power and moves the guide plate between an initial position and a guide position of the guide plate, the controller comprising a switching unit which supplies the DC power to the feed motor so as to move the guide plate between the guide position and the initial position in conjunction with an operation of the exhaust motor, a first limit switch which shuts off the DC power supplied to the feed motor in response to the guide plate reaching the guide position, and a second limit switch which shuts off the DC power supplied to the feed motor in response to the guide plate reaching the initial position.
To achieve the above and/or other aspect of the present invention, there is provided yet another embodiment of the present invention which includes a smoke guiding apparatus of a wall-mounted microwave oven having an exhaust motor which discharges smoke therebelow to the outside of the wall-mounted microwave oven, and a guide plate which guides the smoke, the smoke guiding apparatus comprising a feed motor which receives AC power and moves the guide plate to an initial position or a guide position of the guide plate, a switching unit which supplies the AC power to the feed motor so as to move the guide plate to the guide position in response to the exhaust motor being operated, and supplies the AC power to the feed motor so as to move the guide plate to the initial position in response to the operation of the exhaust motor being stopped, a first limit switch which shuts off the AC power supplied to the feed motor in response to the guide plate reaching the guide position, and a second limit switch which shuts off the AC power supplied to the feed motor in response to the guide plate reaching the initial position.